The first article is a bit misleading in suggesting that the US does not do the same calculation.
It does. In fact, that is the key aspect right now that the CDC is taking into consideration to determine whether or not to subsidize the HPV vaccine.
A very significant number of US policies are determined by that value, not only health related, but also policies relating to the environment, highways. etc.
AP IMPACT: An American Life Worth Less Today - ABC News
In fact, the US system is a bit more encompassing than the UK one, as we do use Bureau of Labor Statistics data to determine the value of life and so on. If anything, the US determination of the value of life is more market based than the UK's. That is, here the value is determined looking more at market data: how much are people spending on treatments that prolong life by X? How does treatment Y affect one's ability to participate on the labor force, and for how long? What would be that person's economic contribution, especially in terms of taxes?
What the US doesn't do, however, is use that figure to negotiate with drug companies. In fact, medicare part D specifically prohibits the government from bargaining with pharmaceutical companies over price.